<!DOCTYPE html>
<html lang="zh">

<head>
    <title></title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.14/dist/vue.js"></script>
    <link href="../css/style.css" rel="stylesheet"> </head>

<body>
    <div id="myApp">
        <h1>用户注册</h1>

        <div>
            <label for="username">用户：</label>
            <input type="text" id="username" v-model.lazy="username" @change="checkUsername">
            <span v-if="checkUsernameOK">可注册</span>
        </div>
        <div>
            <label for="age">年龄：</label>
            <input type="number" id="age" v-model.number="age">
        </div>
        <div>
            <label for="content">个人简介：</label><br/>
            <textarea id="content" v-model.trim="content" cols="55" rows="8"></textarea>
        </div>

        <h4>信息区</h4>
        <p>{{username}}</p>
        <p>{{age}}</p>
        <p><pre>{{content}}</pre></p>
    </div>
    <script>
        var myApp = new Vue({
            el: '#myApp',
            data: {
                username: "",
                checkUsernameOK: false,
                age: "",
                content: "",
            },
            methods: {
                checkUsername: function() {
                    if (this.username.length > 0) this.checkUsernameOK = true;
                    else this.checkUsernameOK = false;
                },
            },
        });
    </script>
</body>

</html>